app/django/contrib/gis/utils/ogrinfo.py
author Lennard de Rijk <ljvderijk@gmail.com>
Fri, 23 Jan 2009 12:00:48 +0000
changeset 920 39badbfb80be
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Added the new way to process invites for club_admin only. This patch contains the separability needed to ensure that we can successfully do the access checks we need. Host invites can for the time being only be completed by developers due to the reorganization. Patch by: Lennard de Rijk Reviewed by: to-be-reviewed

"""
This module includes some utility functions for inspecting the layout
of a GDAL data source -- the functionality is analogous to the output
produced by the `ogrinfo` utility.
"""

from django.contrib.gis.gdal import DataSource
from django.contrib.gis.gdal.geometries import GEO_CLASSES

def ogrinfo(data_source, num_features=10):
    """
    Walks the available layers in the supplied `data_source`, displaying
    the fields for the first `num_features` features.
    """

    # Checking the parameters.
    if isinstance(data_source, str):
        data_source = DataSource(data_source)
    elif isinstance(data_source, DataSource):
        pass
    else:
        raise Exception, 'Data source parameter must be a string or a DataSource object.'

    for i, layer in enumerate(data_source):
        print "data source : %s" % data_source.name
        print "==== layer %s" % i
        print "  shape type: %s" % GEO_CLASSES[layer.geom_type.num].__name__
        print "  # features: %s" % len(layer)
        print "         srs: %s" % layer.srs
        extent_tup = layer.extent.tuple
        print "      extent: %s - %s" % (extent_tup[0:2], extent_tup[2:4])
        print "Displaying the first %s features ====" % num_features

        width = max(*map(len,layer.fields))
        fmt = " %%%ss: %%s" % width
        for j, feature in enumerate(layer[:num_features]):
            print "=== Feature %s" % j
            for fld_name in layer.fields:
                type_name = feature[fld_name].type_name
                output = fmt % (fld_name, type_name)
                val = feature.get(fld_name)
                if val:
                    if isinstance(val, str):
                        val_fmt = ' ("%s")'
                    else:
                        val_fmt = ' (%s)'
                    output += val_fmt % val
                else:
                    output += ' (None)'
                print output

# For backwards compatibility.
sample = ogrinfo